A security group is a virtual firewall that can be associated with an Amazon EC2 instance to control the inbound and outbound traffic for the instance. You can specify which protocols, ports, and source or destination IP ranges are allowed or denied by the security group. A network ACL is a stateless filter that can be associated with a subnet to control the traffic to and from the subnet, but it is not associated with an EC2 instance4. AWS WAF is a web application firewall that helps protect your web applications or APIs against common web exploits that may affect availability, compromise security, or consume excessive resources. VPC route tables are used to determine where network traffic is directed within a VPC or to an internet gateway, virtual private gateway, NAT device, VPC peering connection, or VPC endpoint.